just to further muddy the waters ...
 

In high surface winds with windshear likely on departure, we are allowed to add up to 15 kts to the Vr. Now lets assume that the runway is not limiting, as is often the case on my type, we have a weight book V1/Vr now with a spead of 15kts. Arguably with no FLL the V1 could sit happily under the new Vr, and the takeoff abandoned without compromising safety at that new V1. Problem is that at MTOW, there is no way to reverse calculate an "assumed weight" for the new V1 to check the FLL... probably to stop people scheduling an overweight takeoff with all the liability issues that would go with that.

This is a scenario I can envisage where I see an obvious conflict.
V1 .... long pause ... loud bang at V1+10kts with 2500m of runway ahead, thats almost twice our LDR, the temptation may well be to stop provided no rotation has been initiated.

Defining V1
 

And so the very definition of V1 continues to be debated in the aviation world.

The devil is in the details as one group points out that V1 should really be called "continue/reject action speed". It is the speed at which the first positive action must be taken, not the speed at which you actually make the decision to reject.

A cursory study of available data will show that rejecting above V1 is like trying to win in Las Vegas. The odds are with the house.....

I have only rejected one takeoff and it was at rotation speed in a C23 in Iraq with about 7000 feet of runway in front of me. The flaps were not set properly and the decision was obvious. No harm, no foul. However, as a 744 FO, I don't envy any of my Captain's responsibility to reject a max gross weight whale.....

Why do they do that? Is it because it is too hard to pull back the control column with one hand or is there an operational reason for that or is it merely old fashioned tradition? Its not done in the Airbus (ie two handed rotation on the side stick):ok:

It is experience. If one does not remove the hand from the thrust levers at V1 (or before) chances are very very high that take offs will be routinely aborted above V1.

In the L'Airboos I take my hand off the throttles at V1 and
stick it on the RH armrest of me seat - till its needed to be
back on them again.

A lot of the kids have this damn annoying habit of putting
their mitts all over 'em just after rotation.

JT

I was expecting the performance heavyweights to post in this thread.

When V1 = VR, in what cases it can be ASD limited ?

We can say that in this case, V1 is "maximum", which can be regarded as maximum ASD, minimum TOD V1. If ASDA is not infinite, at least it is enough,.

I always thought that choosing "maximum V1" is done so that we have more chances to stop and stay on the ground rather than taking off.

In the 320 I feel like doing something worthless when I calculate V1 in a 3500 m runway from which 747s and 380s are taking off. All I want to know is VR and V2. Such one day in a wet 4000 m runway we used FCOM 2 tables to substract knots to dry V1, VR and V2. I called out V1, we waited till 10 knots later and called "rotate". I think we had still 2000 m remaining...In some cases V1 is simply ridiculous. In others it has a meaning.

I look at V1 as a decision speed, in the sense that I don't intend to assess the situation too much if something happens during take off. Before V1, stop, at or above V1, go. No thinking. The thinking is made before the event. Obviously I will stop in case of a catastrophic failure. I don't know what happened to that 74 nor how a captain knows that a wing is no fire. An engine fire is no reason for rejecting after rotation, unless you are certain that there is runway enough, and that must be difficult with a 747...

What do you say we speed this thread to it's logical end?

Airlines push balanced field numbers into the over runs and weeds with reduced thrust calculations, under the guise that pushing trend monitored engines out to 30,000 hours, saving a few overhauls is worth the risk of flying it to the end, then pulling up.... Combine this with the common hiring practices of picking from the bottom of the resume pile...the most inexperienced pilots they can hire, specifically culled to take orders...a flying marsh-mellow is trained to read a checklist rather then make a decision...he is told to yank the yoke at V1, fly the wreck into the air...because statistically, if your typical pilot flies 'the numbers'..statistically he should be safe..

- unless he gets ice..
- unless he hits a few birds
- unless his seat rolls back to the rear
- unless lightning knocks out his tubes
- unless he has a flight control failure
- unless he has terrorists on board..

etc etc etc....

This philosophy is based on the idea that all scenarios have been addressed in the sim, and put into checklists...which is wrong. It's also under the guise that statistically given a choice under pressure, pilots will screw it up, make a bad decision...this of course is based on some epic mistakes made by airline captains, and certainly doesn't take into account all the non- accidents, famously averted, that never made the news, by pilots who 'thought' their way out of a jam....and many times famously disregarded the checklists that have been written by the lawyers, trying to fight a future court battle, not avert the current impending accident.

So in an effort to control the safety of airline operations, pilots are told to refer to sops and checklists...and secretly hope that nothing will happen out there, outside of the book...which happens all the time....

A pilot sitting there at the end of a 10,000 foot field, purposely moving v1 farther down the field with reduced thrust calculations, knows full well he is increasing the risk of that departure, so do his boss's, so does the FAA. Trying to justify yanking back on the yoke at V1 is really easy when all you ever see in your career at V1 is the end of the runway will building in front of you.

The rest of us have spent a lifetime flying planes where there is a mile of pavement in front of us, and just can't imagine why you'd take the wreck up in the air when you have the opportunity to safely keep the aircraft on the ground.

Brian,

Au contraire, mon ami, I know all too well the newest version of the resident fanatic (def, someone who won't change their mind and can't change the subject). He was recently over at the Concorde thread explaining to some of the designers and operators of that elegant lady, how much in error they are.

WRH

Or is it, when reality bites? This is well plowed ground, I think.

GF

The pilot of the Emerald 748 had approximately "a mile of pavement" in front of him - the "bang" happened with 1750m remaining, or about 1.1 miles. And his takeoff speed was a fairly low 111kts. Yet even with those favourable conditions, he still overran the far end of the runway at 62kts, a speed high enough to be considered likely to cause a hazardous outcome - which equates to death for some of the passengers or crew. That it didn't in this case was due to a relatively favourable overrun area and the good fortune of missing the approach lights.

Even if the decision was a reasonable one for those circumstances - the AAIB feels it was, and people here have suggested that the specifics of the aircraft/engine concerned go some way to backing that up - the crew were nevertheless wagering what they felt was probable disaster in-air against possible disaster on-ground. Had the outcome of the overrun been even a little worse then I suspect there would have been a lot more official questioning of the captain's decision-making.

Except in the most favourable conditions, conducting a safe rejection from above V1 (or Vr, in this case) will never be an option with any guarantee of a safe outcome; accurately weighing two unknown but high risks in an instant is going to be a challenge for any skill level.

Why dont we just concede that SSG, whenrealityhurts, etc etc etc etc... is right, maybe his flight testing in Microsoft FSX and maybe he is a real pro and uses X-Planes, is correct, and the last 30 years of industry research, analysis and operational reviews are incorrect.

We should bow to his superior knowledge............ Henceforth, I hereby swear that I will not conduct another Flex Thrust Balanced Field Takeoff anytime in the next 24 hours.

Now I want to listen to more of his tales of daring do, I loved the one about him flying in the right seat of a Gulfstream and saving the aircraft, not to mention his tales of single pilot operations in the CJ...... Please oh aviation demigod, tell us more.

Mutt

Hehe, i can swear the same mutt ;) and it is funny how the same character does his jack-in-a-box inpersonation several times a year...

Mutt, Denti, Brian and MfS,

Let's grant that he is an active pilot, who does fly "single pilot" Citations (possibly because of a dearth of willing co-pilots) and is just not up to large airplane operations and is unwilling to learn.

GF

Not a chance GF. Wander over to Rotorheads and search SSG's posts on helicopter aerodynamics and design. You'll learn stuff not even Bell and Sikorsky know. Walter Mitty by name and nature.

Nice try. But unless there is solid technical proof rather than a wild guess to that statement then the reasoning is flawed and a lawyer would tear the proponent's argument apart and rightly so.

Here's another aborted-past-V1 event that occurred in 1996.
Worth taking a look at...

GA865 Report PK-GIE.pdf

I'm not endorsed DC10, but harking back to my 747 days it
would appear to me that 151kt might've been the "highest
V1" in the dry case and so should have been fully respected.

Actually sheppey, there is more than only a technical proof, there is substantial statistical data about it. Which is why boeing made it a mandatory take off procedure, at least on the 737.

V1 for the GO case is computed for an engine failure condition.
V1 for the STOP case is thought for any kind of failure (other than braking systems...)

So if I ever have a malfunction different than an engine failure at or above V1I know that I can continue take off very well!. The airplane will lift off and climb as in a normal take off. In the STOP case, however, there is always a reasonable chance to overrun or depart the runway no matter what kind of failure you have, engine or anything else.

As a rule, GO is better than STOP, the only exceptions being failures or circumstances of a catastrophic nature that render the airplane "unflyable" (terrorist bomb explosion, total flight controls failure...).

The question is "How the heck I know the airplane is unflyable?"

Microburst2002:

Short answer: You probably don't.

TWA lost a 707 at KCVG in 1967 because after V1 the F/O mistook as an engine failure the momentary noise and buffeting from passing through the engine wake of a DAL DC-9 that was stuck in the mud and trying to power his way out.

When V1 = VR, in what cases it can be ASD limited ?

Anytime that ASD happens to be the limiting case. The point being made is that the various limitations are applied separately and whichever is limiting for the particular takeoff sets the RTOW.

If ASDA is not infinite, at least it is enough,.

Fair comment

I always thought that choosing "maximum V1" is done so that we have more chances to stop and stay on the ground rather than taking off.

Not necessarily .. and the other consideration is whether it is a good idea to make a non-limiting ASD situation limiting by pushing the V1 up as high as possible on the day.

Running to maximum V1 gets you to VR in the shortest distance which benefits the go case. Reducing to a low V1 pushes the TOD out for the benefit of a more relaxed ASD.

In some cases V1 is simply ridiculous.

If you have a lot of spare runway in front of you then, consistent with the data presented, you have the option of increasing V1 as you might see fit. Be wary of brake energy limits ...

The thinking is made before the event.

And that is the basis for risk managing SOPs.

aerosafety world
 

in this month issue there is an article about this very thread topic, related with a 737 that did RTO some 10 kt above V1, and survived. very interesting.

Well thanks guys. Seems my original hypothesis was about right. But who the heck is this notorious SSG? He hasn't even posted here AFAIK.

Have a look at this thread.... there are many more as he changes his persona......
He asks extremely interesting questions, but he isn't willing to listen to comments from others, unfortunately :{:{
I would love if he would just start the questions and then listen to the answers, but arguing that the whole concept of reduced thrust is wrong, or aborting after V1 is a normal event are a lost cause.

Mutt

Mutt -

Your religion is crumbling...

CRM and Ab Initio new hires, are dying a well deserved death.....

It's only a matter of time when another fool who 'pulls it off no matter what at V1, then flies the unflyable to the scene of the accident' puts Flex and 30000 hour engines on the block as well.

I promised myself I wouldn't do it, but here goes.....

WRH

Please post on accident report where an airliner, having an emergency of any type, continued the take-off, instead of stopping, got airborne and CRASHED. Also, please provide an accident report citing, reduced thrust take-offs, on-condition engine monitoring or a case where good CRM as causal or contributing to the event.

Do so, and expect some grudging acknowledgement.

GF

JT

you are right. Of course take off can be ASD limited with VR and V1 being equal. However I have very rarely seen a runway limited case. Most of the times second segment or obstacles is the limitation. (by the way, Can that be the reason for the high V1 VR values, that the optimum speeds are sort of an improved climb?)

others

Nobody will fly a wreck if he knows that it is a wreck. It is better to stop a wreck and overrun the runway than become airborne and crash.

The problem, however, is how to determine what the airplane's status is: wreck or not wreck.

This would be difficult even if we had 5 minutes to analize the situation.

At 140 kt ground speed we are running about 70m per second, and quickly accelerating, so in a few seconds we may have "eaten" hundreds of meters. furthermore, the speed gained goes squared in the kinetic energy equation. If we have already started rotation, things are even worse because efficient braking action will be delayed for more seconds. The result is several hundred meters lost plus some other several hundred extra meters needed for stopping. If the take off was already ASD limited, or approximately, then you have a runway excursion.

We don't have time to assess, only to react. If we react instictively we can screw it totally, unless we have spiderman's arachnid sense. So we need to use other form of decision making: anticipated decision making. The flaw of this method is that you don't know all the possible scenarios. You don't know what will happen. But the good thing is that chances of choosing the correct action are much better than in the instinctive reaction. Much better, i'd dare to say. OF course we can be unlucky and choose GO the damned day that the airplane is a wreck...

Airbus policy regarding RTO is very interesting, and it leaves a lot of room for Captain's decision. The ECAM inhibit function is very helpful and ergonomic, by the way. I guess Boeing has a similar feature?

Well said Microburst

Yes, the Boeing also inhibits certain warnings, fire for example, at certain speeds during the take off.

Another DC-10 "reject after V1" overrun at Vancouver in 1995, but with a better outcome than the Garuda accident:

Transportation Safety Board of Canada - AVIATION REPORTS - 1995 - A95H0015

And that last statement SSG, is exactly what you are trying to do to people.

Mutt

Report: B737-800 rejected takeoff after V1

The Dutch Safety Board published the findings of their investigtion into a serious incident at Eindhoven Airport when the takeoff was rejected after the takeoff decision speed (V1).The Boeing 737-800 operated by Ryanair was taking off from runway 04 on the 4th of June 2010 at Eindhoven Airport, the Netherlands. At the time of rotating the aircraft to takeoff, the pilot flying decided to reject the takeoff because he believed the aircraft was unsafe to fly. The decision to reject was made after the takeoff decision speed (V1). The pilot performed a so-called high speed rejected takeoff.
The aircraft was halted before the end of the runway and the aircraft was subsequently taxied back to the terminal. The aircraft sustained no damage and no passengers or crew were injured.
The Safety Board concluded:
During the takeoff at Eindhoven airport the pilot flying perceived two control issues and one speed trend vector anomaly.

• The explanation for the control issues and speed trend vector anomaly was likely related to an outside atmospheric phenomenon. The origin of this atmospheric phenomenon could not be determined or explained with the information available.

The takeoff was rejected after the decision speed V1 and while the nose wheel was off the ground for approximately two seconds.

• The First Officer who was the pilot flying considered the control and speed trend vector problems to be serious enough and decided to reject the takeoff.
• According to company procedures only the Captain is authorized to make a rejected takeoff decision.
• To reject a takeoff above V1, especially when the nose wheel is off the ground, is in principle considered to be improper and unsafe.

There is no specific guidance from the operator or manufacturer on dealing with control issues at the time of rotating the aircraft.

• Specific guidance on rejecting a takeoff exist in case of an engine failure.
• Review of past statistics and studies show that pilot training and requirements focus on rejected takeoffs due to an engine failure. Studies and statistical information show that this accounts for less than 25% of the reasons for rejected takeoffs. Thus 75% of the reasons they reject a takeoff is not trained for.

This incident was discussed on R&N for a while. Consider:

• The V1 speed is artificially reduced to be below VR, as such the V1 speed is NOT the maximum or limiting speed which it is possible to reject the take-off, if the aircraft wheels are still in contact with the runway (i.e. the V1 speed used for take-off is not necessarily limited by either runway length OR brake energy limits) - that speed limit isn't calculated, but can be intuited by an experienced pilot.
• The V1 decision is only trained for engine failure - not for control problems or un-flyable conditions. If the aircraft is considered un-flyable, then a reject at ANY speed is appropriate.
• In the same sense that a Captain may disregard SOPs in an emergency situation when the Captain considers the aircraft is under threat - does not the same apply to a licensed and qualified FO, when the aircraft is considered under threat - and there is no time to consult with the Captain?
• In this case - the aircraft stopped, and taxied back without problems - so 20:20 hindsight says that the FO didn't endanger the aircraft by stopping.

Thanks Checker...your right, the results speak for themselves.

Amazing how many guys would watch a non-event RTO and still think the pilots should have pulled it off into the soup and fought the problem up there....

I thought it perhaps worthwhile to post the following from the 738 reject report, as it highlights the difficulties faced in the decision making process at an extremely critical time.

http://www.onderzoeksraad.nl/docs/ra...yan_Air_EN.pdf

REJECTED TAKEOFFS IN A HISTORICAL PERSPECTIVE

Rejected takeoffs are not uncommon and in the past have resulted into accidents. Several studies and investigations were performed on rejected takeoffs, a general overview of these studies will follow. In 1990 a Special Investigation Report Runway Overruns following high speed rejected takeoffs was published by the National Transportation Safety Board (NTSB) of the United States of America. The NTSB conducted this investigation to determine how the safety of rejected takeoffs could be enhanced and the rate of incidents reduced. The investigation used a variety of information on rejected takeoffs including historical accident data and airline procedures. In this special investigation report several recommendation are made to the Federal Aviation Administration (FAA) on improving safety for rejected takeoffs. An overview of the recommendations are presented in appendix H. In 1994 the FAA in a joined effort with industry created a training tool for rejected takeoffs, the Takeoff Safety Training Aid. The main purpose of this training tool was to reduce the number of rejected takeoffs by improving flight crew decision making process, knowledge and awareness. The Takeoff Safety Training Aid describes the background of events and lays down training methods and simulator scenarios for pilot training on rejected takeoff decision making. The “Takeoff Safety Training Aid” training program is designed to facilitate flight crews in reaching and maintaining proficiency in:

• Recognising and understanding situations and factors that make high speed rejected takeoff decisions critical.

• Making appropriate Go/No Go decisions.

• Executing rejected takeoff procedures and employing techniques that maximises the stopping capability of the airplane should a high speed rejected takeoff be necessary.

• Continuing the takeoff safely should that be deemed the most appropriate course of action. In this safety training aid, data and background information on rejected takeoffs from 1959 up to 1990 is presented. It is reported that 76% of all rejected takeoffs are initiated at speeds of 80 knots or less. The rejected takeoffs at low speed almost never result in an accident. About 2% of the rejected takeoffs are initiated at speeds above 120 knots. Statistically more than half of the runway overruns or excursions have occurred when the rejected takeoffs were initiated at high speeds (greater than V1).

REJECT SPEED

80 knots or less 76%
80 – 100 knotsx 18%
100 – 120 knotsx 4%
Above 120 knots 2%

According to the Takeoff Safety Training Aid in the event the airspeed is beyond V1 a “go decision” is less hazardous and the takeoff should therefore not be rejected. The reasoning is that the problem faced by the flight crew may be handled more safely as an in-flight problem than a high speed rejected takeoff. The reasons for rejecting a takeoff vary from an indicator/light to wheel or tire failure.

REASONS FOR REJECT

Enginexxxxxxxxxxxxxxxxx24.3%
Wheel/Tyrexxxxxxxxxxxx22.9%
Other and not reported 13.5%
Configurationxxxxxxxxxx12.2%
Indicator/Lightxxxxxxxxxx9.5%
Crew Coordinationxxxxxxx8.1%
Birdstrikexxxxxxxxxxxxxxx6.8%
ATCxxxxxxxxxxxxxxxxxxxx2.7%

In an advisory circular AC no: 120-62 the FAA recommends the use of the Takeoff Safety Training Aid to operators. It is recommended that the training aid is incorporated in the operators flight crew training and qualification programs of operators. FAA inspectors are required to check the operators manuals and training to asses if the Takeoff Safety Training Aid is used and guidelines are followed. In 2004 the pilot guide to takeoff safety (section 2 of the training aid) was updated. The study period was extended from 1959 up to 2003 and accident data was supplemented with 25 additional rejected takeoffs. The additional data showed that the rate of rejected takeoff decreased. The engine related rejecting takeoffs decreased and wheel/tire failures increased by a small percentage. In late 2006, the Flight Safety Foundation initiated a project entitled Runway Safety Initiative (RSI) to address the challenge of runway safety. An in-depth study was conducted of all runway excursion accidents from 1995 through March 2008 to investigate the causes of runway excursion accidents and to identify the high-risk factors. Data was analysed to identify the most common risk factors, both in takeoff excursions and landing excursions. The most common risk factor in takeoff excursions was a rejected takeoff initiated at a speed greater than V1. Loss of pilot directional control was the next most common, followed by rejecting the takeoff before V1 was reached. This study concludes that a mishandled rejected takeoff increases the risk of takeoff runway excursion. Operators should emphasise and train for proper execution of the rejected takeoff decision and training should emphasise recognition of takeoff rejection issues. Furthermore Cockpit Resource Management and adherence to Standard Operating Procedures are essential in time-critical situations such as rejected takeoffs. A recent study (2010) by the National Aerospace Laboratory, in the Netherlands compared rejected takeoff events for the period 1980-1993 with the period 1994-2008. The split 1993-1994 was chosen because in 1994 the Takeoff Safety Training Aid was introduced. The NLR study shows that the occurrence rate of rejected takeoffs in general has decreased, however the rate of high speed rejected takeoffs has not changed. In the NLR study the decision to reject a takeoff is also examined. The study shows that the correctness of the decision to reject a takeoff before and after 1994, the introduction of the Takeoff Safety Training Aid, has not increased. The statistical information on the correctness of the decision to reject a takeoff is based on hindsight. Pilots at the time thought they were making the right decision. The study concludes that especially in complex situations, for example a combination of engine failure with significant vibration, it is difficult to assess. Assessing a complex situation and deciding to reject the takeoff is also not well trained. The study points out that the lack of reference as to what might make the aircraft unsafe to fly makes it difficult for crews in recognising such a situation to make an appropriate decision. It should be noted that care must be taken in comparing the positive (yes) and negative (no) decision to reject the takeoff. The undetermined reasons of correctness of the decision has increased in the period 1994-2008 versus 1980-1993.

REJECTED TAKEOFF DILEMMA

In the past industry initiatives and studies have identified that rejected takeoffs are a high risk area. Analysis of available data highlighted that after V1 and VR a runway overrun is likely and could potentially result in aircraft damage and/or loss of life. Statistics further show that the rate of rejected takeoff is declining. However the rate of high speed rejected takeoffs is not. In general past studies conclude that if procedures were followed the outcome would have been different. This conclusion it subsequently followed by the recommendation that flight crew should follow procedures and act accordingly. Despite simulator training on rejected takeoffs and instruction on the risks of (high speed) rejected takeoffs flight crews, when faced with a problem in reality, do not always react desirably and follow procedures. This is mainly due to the fact that during takeoff the interaction between the aircraft, environment and crew are tightly related. This interaction may result in a complex situation which is unfamiliar and difficult to assess. Technical monitoring and warning system were introduced into aircraft in the past which, when appropriate, would warn flight crew of a problem. This warning system monitors aircraft condition and should help flight crew in assessing situations correctly. In this event no warnings were triggered and the aircraft did not indicate there was a problem. From a manufacture standpoint the aircraft was therefore airworthy and safe to fly. The control check performed before flight is, in part, to assess the aircraft state and verify control responses. The environmental conditions like snow and rain on a runway are addressed in manuals to help flight crew in determining aircraft performance and make adjustments. This information is used to set preconditions and determine decision speeds. The fact remains that despite aircraft monitoring and managing preconditions impacting aircraft performance unexpected situation may occur. On takeoff the flight crew rely on perception and interpretation of situations. This perception and interpretation provides opportunity for errors in decision making. Guidance, procedures and training should help pilots in the decision making process in the critical phase of flight. With the current state of technology and human factors theories available, a re-evaluation of the rejected takeoff concept and procedures may be useful and warranted.

I have very rarely seen a runway limited case.

Depends on Type and runway. I have worked with operators where the limitation on RTOW was just about invariably runway length.

Most of the times second segment or obstacles is the limitation.

Often the case but cannot be relied to be so. A problem is that the RTOW chart may not explicitly state the limiting case on the day.

Can that be the reason for the high V1 VR values, that the optimum speeds are sort of an improved climb?

Certainly, one wouldn't normally be looking to exploit improved climb by pushing the V1 down.

It is better to stop a wreck and overrun the runway than become airborne and crash.

All a risk management exercise. If the overrun is benign, of course. If tiger country (eg have a look at Nauru) perhaps not so clearcut. However, what is clear is that SOPs cover the reasonably routine - a well trained and educated captain gets to handle the hard ones .. presents a problem if the captain is a bit underdone.

But the good thing is that chances of choosing the correct action are much better than in the instinctive reaction.

That's the one. Run with the numbers and keep your fingers crossed that today you are not at the wrong end of the distribution curve.

It is, however, necessary to understand that there are occasions where the normal gameplan(s) won't work and, if you get it right (or at least get away with it), you get the bouquets (Sioux City, the Hudson, and a few others come to mind). If things don't work out so well (we don't need to cite instances) then folks tend to look down their noses.

The captain is called on to make a decision and implement it. The important thing is that a rational decision be made .. longterm fence sitting generally doesn't cut it. The outcome often involves a bit of planning, a bit of skill, and a LOT of luck.

ssg to follow

... that's a bit cruel ?

V1
 

I guess V1 is limited by all of the following factors
* Vstall speed
*Vmcg
*Vmca
*Vmu
and the runway length should also be a limiting factor , guys just correct me if I am wrong in any points

I don't see any reason why they should. Smaller airplanes have smaller wheels, brakes and tires to go along with their diminutive mass. And they routinely operate into much shorter runways. In the bizjet types I've flown, we run up against most of the same performance limitations as any other transport category airplane does. The same analytical approach to takeoff performance planning is required and the same penalties for any miscalculation or ham-fisted execution apply. Do it wrong and you might not like the results.

So no. I don't think the thought process is or should be all that different. Except that nobody does it for you. You have to know how to do it yourself.

Hand on T.R.
 

Centaurus,
One of the reasons for removing the hand from the thrust levers at V1 is to prevent the TRs from going to idle should the seat slide back on rotation with your hand on them. Would be fatal !!

Galaxy flyer,
I remember a DC8 crash where on a severe bounced landing the go around was initiated with the wing on fire. It crashed 2 miles from the airport after the wing burnt off and it went in. I'm sure there are others if we look for them.

Pilots that have a preconceived idea that should they feel that the aircraft is not fit to fly, that they will stop even after V1

The general rule is along the lines that the pilot has to have a conviction that the aircraft is not going to fly .. unless the wingtip is dragging on the ground, the aircraft is blazing away on fire, three engines have failed after going through the flock of birds .. or something of like ilk, that's a big call.

The exception should never be used to argue a rule .. rather, in just about every case, we are better off running with the SOP .. if we die, it just wasn't our day to go flying. He who runs on a wing and a prayer and acts capriciously .. probably will end up dying far earlier than the rest of us.

I accept that a Citation pilot may have a different thought process

Long time since I looked at a Citation AFM but, as I vaguely recall, it has a very low Vmc and overall pretty good field length figures ?

Things are not always as clear cut as you would like us to believe. Read the human factors section on this,

http://www.fomento.es/NR/rdonlyres/2...x_English1.pdf

And another,

http://www.ntsb.gov/doclib/recletter...10-046-059.pdf

Perhaps they would have fared better had they pulled it into the soup and fought the problem up there. But hind sight is always 20/20 heh SSG. (No criticism implied or intended of the crews).

In a rare exception to following SOPs, a GF colleague flying a TriStar in the eighties abandoned just after V1.
I'm sure this will be read by those who remember a bit better than I but, IIRC:
Something went 'BANG!'
They stopped.
Subsequently discovered that only 'D' hydraulic system remained.
'D' system didn't do very much. :ooh:

The common thinking in aviation is to find answers, post crash, and use those answers as a preventative to future similar problems...this is of course a hypothetical solution to a real problem.

When an aircraft simply pulls the throttles back post V1, only to taxi back to a hanger, find a mechanic...it's not even an incident, never makes the NTSB reporter, much less an FAA call...and how many times has this happened...more then you realize.

The myopic view of aviation is to look at all the accidents, typically performed by pilots at their worst, then somehow find consensus with those sad folks, rather then look at the pilots who took a potential newsworthy accident, turned it into a non issue...the answer therein lies with those that have successfully found outcomes to the problem at hand, not trying to find answers in the rubble of idiots who couldn't.

I'm not saying we shouldn't look at accidents, but why should I be held to a SOP because some moron crashed the plane, because he made a bad decision, or by some airline that hires from the bottom of the resume pile, using 'Flex to the Fence, etc etc.???